1. Field of the Invention
The present invention relates to dielectric ceramic compositions, and particularly to dielectric ceramic compositions for use in monolithic ceramic capacitors having inner electrodes made essentially of silver-palladium (Ag-Pd).
2. Description of the Related Art
Ceramic capacitors for temperature compensation use have been used widely in tuning circuits, resonance circuits, etc. Since small-sized ceramic capacitors having a small dielectric loss and stable dielectric characteristics are preferred, dielectric ceramics for such capacitor applications desirably have a high specific inductive capacity and a small dielectric loss, i.e., a large Q value.
Monolithic ceramic capacitors using dielectric ceramic compositions having the above-mentioned characteristics have been put into practical use. However, since the firing temperature of dielectric ceramics is as high as 1300.degree. C. to 1400.degree. C., palladium, platinum or a like material having a high melting point must be used as a material for inner electrodes. One problem with these electrode materials is their high prices.
Ag-Pd is an electrode material less expensive than Pd and Pt. The melting point of Ag is 961.degree. C. As the Ag content of an electrode material increases, the electrode material cost reduces; however, the firing temperature of a dielectric ceramic must be lowered accordingly. Specifically, there is demand for a dielectric ceramic composition that can be fired at a firing temperature up to about 1250.degree. C.